The present invention relates to methods for fabricating a plated product with a base on which a basecoat layer, a metal plating layer, and a topcoat layer are formed, and, more particularly, to methods for fabricating a plated product that prevents the surface of a metal plating layer from being discolored by impurities.
For example, Japanese Laid-Open Patent Publication No. 10-309774 describes a method for fabricating a layered body with a silver plating layer. The layered body includes a base, an undercoat layer, the silver plating layer, and a topcoat layer. The undercoat layer is formed by drying an undercoat agent, or a varnish that contains alkoxy-titanium-ester and at least either a silane coupling agent with epoxy radicals or epoxy resin.
To form the layered body, the undercoat agent is applied to the surface of the base and is dried to obtain the undercoat layer. Subsequently, an aqueous solution of silver is applied to the surface of the undercoat layer and is dried to form the silver plating layer. The topcoat layer is then formed on the surface of the silver plating layer. The method of the aforementioned patent publication is applicable to layered products with various bases such as insulating or conductive bases. Further, as fabricated by this method, the layered body has the silver plating layer and the undercoat layer that are securely bonded together, and the durability of the layered body is improved. That is, the method makes it possible to efficiently and easily fabricate a layered body that has a silver plating layer with an improved property.
However, if the silver plating layer of the layered body contains even a small quantity of impurities, the impurities are naturally oxidized to discolor the surface of the silver plating layer to a yellowish tone, thus hampering the appearance of the layered body.
Accordingly, to solve the aforementioned problem, it is an objective of the present invention to provide a method for fabricating a plated product that easily prevents the surface of a metal plating layer from being discolored by impurities.
To achieve the foregoing and other objectives and in accordance with the purpose of the present invention, the invention provides a method for fabricating a plated product with a basecoat layer, a metal plating layer, and a topcoat layer that are formed on a surface of a base. The method includes the steps of forming the basecoat layer and the metal plating layer successively on the surface of the base, removing impurities from a surface of the metal plating layer after the formation of the basecoat layer and the metal plating layer, and forming the topcoat layer on the surface of the metal plating layer after the removal of the impurities.
A further perspective of the present invention is a method for fabricating a plated product with a basecoat layer, a metal plating layer, and a topcoat layer that are formed on a surface of a base. The method includes the steps of forming the basecoat layer and the metal plating layer on the surface of the base, forming an antioxidant film on a surface of the metal plating layer after the formation of the basecoat layer and the metal plating layer, and forming the topcoat layer on the surface of the metal plating layer after the formation of the antioxidant film.
A further perspective of the present invention is a method for fabricating a plated product with a basecoat layer, a metal plating layer, and a topcoat layer that are formed on a surface of a base. The method includes the steps of forming the basecoat layer and the metal plating layer on the surface of the base, disintegrating impurities by applying an acid to a surface of the metal plating layer or immersing the surface of the metal plating layer in the acid after the formation of the basecoat layer and the metal plating layer, adsorbing the impurities by applying a protein dispersed solution to the surface of the metal plating layer or immersing the surface of the metal plating layer in the solution after the disintegration of the impurities, and forming the topcoat layer on the surface of the metal plating layer after the adsorption of the impurities.
A further perspective of the present invention is a method for fabricating a plated product with a basecoat layer, a metal plating layer, and a topcoat layer that are formed on a surface of a base. The method includes the step of forming the basecoat layer on the surface of the base. The basecoat layer is obtained by applying a basecoat agent to the surface of the base or immersing the surface of the base in the basecoat agent and drying the basecoat agent on the surface of the base. The method also includes the step of forming the metal plating layer on the basecoat layer. The metal plating layer is obtained by a chemical silver plating method. The method further includes the step of removing impurities from the surface of the metal plating layer after the formation of the basecoat layer and the metal plating layer and the step of forming the topcoat layer on the surface of the metal plating layer after the removal of the impurities.
A further perspective of the present invention is a plated product with a basecoat layer, a metal plating layer, and a topcoat layer that are formed on a surface of a base. The metal plating layer is formed of silver. The value xcex94b* obtained by subtracting the colorimetric value b* of a standard wet type plated product of Chromium(VI) from the value b* of the plated product, as measured in accordance with Lab color system, is lower than or equal to five.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.